A novel dual band tunable balanced handset antenna for WLAN application

This paper presents a tunable balanced antenna covering WLAN frequency bands near 2.4 GHz (2.4-2.4835 GHz) and 5 GHz (5.15-5.35 GHz & 5.650-5.925 GHz), for mobile application. The design is based on loading two variable capacitors onto the planar balanced antenna to electronically tune its resonant frequency; the higher frequency was tuned with the capacitance varying from 0.1pf to 0.3pf, while the lower frequency band remains constant. Performance of the proposed antenna was analyzed and optimized against the two targeted frequency bands. For validation, the antenna prototype was fabricated and tested then the measured results were compared to simulation ones. The performance of this proposed antenna was verified and characterized in terms of the antenna reflection coefficient |S₁₁|, radiation pattern and power gain.